The Wang 362E was the last and most
feature-packed machine in the Wang 300-series of calculators.
The 362E represents the end of the line for the 300-series, as by the time
it was introduced (May of 1968), calculators from competitors such as
Hewlett Packard (an example being the HP 9100B)
had eclipsed the 300-series in capability and speed. Wang
had to come up with a new, cutting-edge calculator architecture quickly or
risk losing large amounts of its lucrative market share to
new competitors in the marketplace. HP's 9100-series calculators had many
more features and capabilities than Wang's machines, were much faster, and
were self-contained in a single desktop
package, making them extremely desirable to customers looking for an advanced
calculator. Wang Labs' had been caught somewhat by surprise by the actions of
competitors. They had become a bit complacent, basking in the glow of the
extraordinary success of the 300-series. The announcement of HP's
new calculators, along with other forces in the market, forced the
president of Wang Laboratories, Dr. An Wang, to make a quick decision.
Wang Labs had been working on a project to develop a new business. Dr. Wang
saw the meteroic success of Digital Equipment Corporation, and their
brilliantly simple mini-computer, the PDP-8. A project had been initiated to
build a computer that would beat Digital Equipment at their own game, and
place Wang in a leadership position in the mini-computer market.
However, because Wang's calculator business was the primary source for
revenue for the company, and the competitors had very quickly begun taking away
a serious chunk of the business, Dr. Wang's reaction was to do a hasty rework
of the mini-computer project. The mini-computer design that had been developed
thus far was modified to change it into a very powerful programmable
calculator. This redirection of Wang's computer effort brought rise to
the Wang 700-series calculators (for example, the
Wang 720C), which was a very capable machine
that allowed Wang to recapture some of its lost market share. The problem
Wang had was timing. There was a period of time between the competitor's
calculator introductions (and their almost immediate erosion of Wang's
stranglehold on the high-end calculator market), and the time that Wang's
700-series machines were ready (mid-1970) for the marketplace. Something
was needed to fill this gap, to stem the loss of sales to competing
calculator makers.

Wang 362E Model/Serial Number Sticker

The earlier members of the 300-series,
such as the Wang 360E, had fairly limited memory
capacity, and their programming capabilities were rather primitive. A
300-series machine was needed that would allow Wang
a little more fight out of the aging 300-series until the 700-series
was ready. In order to provide better data-storage capabilities,
the 300-series architecture was augmented to add more memory registers,
as well as provide for direct memory register arithmetic. These fairly
subtle changes to the 300-series architecture became the 362E, the interim
calculator developed to fend off the competition while the 700-series
was being developed. Wang's strategy was to convince the potential customer
needing a more advanced calculator that a Wang 362E electronics package
connected up to a Wang 370 or
380 "Programmer" would give them
the basic features they needed, at a lower price than the competitors.
Wang deeply discounted the prices on 300-series machines as part of this
strategy to make the machines more attractive. To sweeten the deal, Wang
would arrange a sizable credit to the customer for the trade-in of the
300-series system in exchange for a 700-series calculator once the 700-series
machines were available. In some cases, Wang provided very inexpensive
short-term leases on 300-series calculators to customers who were considering
buying a competitor's calculator, just to get the deal and sell the customer a
700-series machine later.

Along with the fact that the 300-series calculator's capabilities were
starting to become less of a selling point in the growing high-end
calculator marketplace, another factor contributed
to the competitive demise of the 300-series, the aging of the technology
used to make them. The 300-series
calculators were discrete transistor designs. There are no
integrated circuits (also called "microcircuits") in these machines.
At the time the 300-series calculators were designed (during the late part of
the early 1960's), integrated circuits were simply too expensive.
IC's were used primarily in military and computer applications where
their cost was more easily handled by the needs of these demanding
markets. Military weapons systems and large mainframe
computers were markets that had lots of money behind them. During
the height of the Cold War, military contractors needed to cram increasingly
more sophisticated weapons electronics, radar systems, and avionics into
very limited space, along with stringent weight and power specifications.
The only way to meet the requirements was with integrated circuits. Large scale
mainframe computers were required to be faster and more capable to handle
the exponentially growing computing needs of large business and
government. Computer manufacturers also had to resort to IC's, as the
limits of transistor technology made building computers out of discrete
components impractical. In the world of calculators, though, transistors
were inexpensive and plentiful, were a well-known technology for the
electronics engineers of the time, and, with the limited complexity of
a calculator, were very practical for use as the mainstay implementation
technology for a calculator. That is, until the late 1960's, when the cost
of integrated circuits had began to come down. Japanese calculator
manufacturers such as
Casio(Casio 121/Commodore 1121,
Sharp(Compet 16), and
Hitachi(Singer/Friden EC1113), among others,
had begun using small and medium-scale IC's in their calculators. The use
of integrated circuits substantially reduced the size and cost of calculators,
and increased the machines' capabilities and speed. This technology
pressure also contributed to the end of development for the Wang 300-series
calculators, as their all discrete component design meant that the machines
were more complicated to build, took up more space, were less reliable, and
used more electricity than the up and coming calculators from Japan that used
integrated circuit technology. The 700-series calculators were designed
using integrated circuits because a machine with such capabilities
was simply way too impractical to build using the discrete-transistor
technology of the 300-series calculators.

Warning Sticker - Not Good to Unplug the Keyboard/Display Unit with Power Applied

Like all of the other Wang 300-series calculators, the 362E system consists
of an electronics package that contains all of the circuitry
that performs the calculations, and a separate keyboard/display unit that
plugs into the electronics package (which can be located up to 200 ft.
away). From a functional perspective, the Wang 362E is identical to the
Wang 360E and other members of the 300-series,
with the exception of its additional memory register capabilities.
As with all of the members of the 300-series, the 362E has a numerical capacity
of 10 digits, with 14-digits maintained internally to provide more accurate
results. All 300-series calculators operate with full-floating decimal point,
and share a complement of four working registers; two accumulator registers
(called the "Left" and "Right" adders), the "Working" register (where numbers
are entered, and results placed), and the "Log" register.

The Log register,
part of Wang's unique digital log/antilog
generation circuitry, is used for performing multiplication and division,
along with the square, square root, natural logarithm, and natural
antilogarithm functions. This electronic logarithm generation circuitry
is what gave Wang's first-generation LOCI
calculators, and the 300-series machines the built-in scientific capabilities
that bettered competitor's calculators and gave Wang Laboratories a dramatic
lead in the high-end calculator marketplace from the late part of the
early 1960's, though around 1968, when the competitors finally caught up.

Mechanical Assembly Quality Assurance Sticker (Located inside unit)

This particular 362E was mechanically
assembled in late June of 1969, and received it's final pre-ship Quality
Assurance inspection on May 30, 1970. It is clear that Wang inventoried
mechanical assemblies (chassis/backplane/power supply), and a supply
of Logicblocs. When a customer ordered a unit,
the Logiblocs were installed in a waiting chassic, the assembly tested
and given final inspection, and shipped. This is why the mechanical
QA sticker (seen above) and the final QA sticker (unable to image due to
fading) have different dates. The final QA sticker (usually located on
the bottom of the electronics package right next to the model/serial
number tag) should have a date that is later than the mechanical inspection
tag (usually located inside the cabinet, on the backplane side of the
chassis, near the power supply).

The distinguishing feature of the 362E
is its extended memory functionality versus other memory-capable machines
in the 300-series. The Wang 360E, 320SE, and
360SE calculators provide four independent
store/recall memory registers. Each of the four registers
may have a number deposited into them, or recalled. On these
machines, a total of eight memory function keys provide access to the four
memory registers, with each set of two keys providing a "STORE" and "RECALL"
function for each of the four registers.

The 362K Keyboard Layout

The 362E marked a rather dramatic
departure from the memory register architecture of the earlier 300-series
machines, providing a total of 12 memory registers which also function
as accumulators, as opposed to the 'store/recall' function of earlier
machines. Because it would be impractical to provide individual keys on
the keyboard unit to provide store/recall/add/subtract keys for each of the
twelve memory registers (that would be 48 keys!), Wang opted to make memory
access on the 362E a two step process, with the first keypress designating the
memory function (store/recall/add/subtract) and the second keypress selecting
which of the twelve memory registers the operation is to be performed upon.
The memory registers on the 362E are numbered zero through eleven, with
registers zero through nine addressed by a press of the corresponding key
on the numeric keypad. Register ten is addressed by pressing the [CLEAR
DISPLAY] key, and register eleven is addressed by pressing the [CHANGE SIGN]
key. So, for example, to recall memory register ten to the display, the
[RECALL FULL] (more on why the "FULL" designation is included later) key would
be pressed to indicate to the machine that a recall operation is to be peformed,
and then the [CLEAR DISPLAY] key would be pressed to indicate memory register
10 is the register whose contents should be recalled to the display.

To provide even more capability to the
memory function of the 362E, Wang added the ability to divide each memory
register into two half-registers, allowing up to 24 numbers (of reduced
magnitude) to be stored in the memory system. The capability to store
up to 24 numbers allowed the 362E to be able to perform small matrix
manipulation operations -- an important feature for tasks such as solving
systems of simultaneous linear equations and statistics operations.
How this half-register function works requires a bit of digging into
the general register storage architecture of the 300-series calculators.

Silk-Screened "Brag Tag" Proudly Adorning the Top Surface of the 362E Electronics Package

As mentioned earlier, the Wang 300-series
calculators all use small-capacity magnetic core memory arrays to provide
the storage for the operating registers of the machine (Left Accumulator,
Right Accumulator, Logarithm Register, and memory registers on machines
so-equipped). Also mentioned earlier, each register contains fourteen
digits, with ten digits represented to the user on the display, and four
'hidden' digits used to increase the accuracy of scientific functions.
Along with the fourteen digits in each register, it is necessary to keep
track of two more pieces of information for each number stored in a
register -- the location of the decimal point, and the sign of the number.
In the Wang 300-series calculators, an additional digit position is used
to indicate the decimal point location, and the sign of the number.
This means that each register consists of sixteen decimal digits.
The 300-series calculators represent decimal digits in Binary-Coded Decimal
form, where the digits zero through nine are represented by their binary
representation (e.g., 0=0000, 1=0001, 2=0010, 3=0011, ..., 9=1001). It takes
four bits to represent each decimal digit, so a total of 64
bits comprise a register in the core memory of the 300-series machines.
As an example, to represent the number "+123.456", the internal
represetnation would contain the fourteen digits "12345600000000", along
with two additional digits to define the decimal point location (3) and
the sign of the number (0).

The decimal point location is represented
by the number of digit positions the decimal is located within the number
from the left-most digit position, beginning with zero representing the
decimal point being located before the left-most digit. In the example
above, this would be '3'. In the number "6.23", the decimal point location
would be '1', and for "23456.12", the decimal point representation would
be '5'. The sign of the number is represented by a digit of "0000" if
the number is positive, and "1111" if the number is negative. Back to our
example of +123.456, we end up with

being stored into the 64-bit core memory
location. The first four bits represent the sign of the number. The next
56 bits represent the number itself ("12345600000000"),
the last four bits are the decimal point location.

Now that the method of storage
of numbers in the calculator is understood, it is possible to explain
the concept of dividing the twelve full memory registers in half to provide
24 'half-sized' registers. Each half-register consists of 32 bits,
24 of which store the number itself, four bits representing the decimal
point location within the number, and four bits representing the sign.
Using this means, each 'half' register can store a number in the range
of -999999 to +999999. The halves are referred to as the "A" and "B"
halves of each register. For example, the "A" half of register eight could
store the number "254.3", and the "B" half could have "-1086.55".
This would be represented the 64 bits of storage register eight as follows:

Given this organization, a total of eight
memory function keys (the same number used on the earlier calculators with
memory functionality) can control the operation of the memory on the 362E.
The eight memory functions are [STORE FULL] and [RECALL FULL] (which
store or recall a full memory register), [ADD FULL] and [SUB FULL] (which
add or subtract the number in the display to the selected full memory
register), [STORE HA] and [STORE HB], which store the
number currently in the display (truncated to the most significant six digits)
into the "A" or "B" half of the selected memory register, and lastly,
[RECALL HA] and [RECALL HB] which recall the A or B
portion of the selected memory register to the display. The beauty of this
design is that existing Wang 300-series keyboard units with memory function
keys can be used on the 362E by simply changing the keycap nomenclature on
the eight memory function control keys to indiciate the 362E's memory
functions. The Wang 360K and 360KT/KT keyboard/display units
can be used on the early 300-series memory-capable electronics packages
(360E, 320SE, 360SE), or on the 362E by simply changing the paper keycap
labels. This design meant that Wang could re-use these keyboard units with
no changes other than making new paper legends for the keycaps. This rather
elegant enhanced memory architecture helped keep costs of the 362E down, as Wang
didn't have to design new keyboard/display units to work with the different
memory architecture of the 362E. In fact, once the 362E was introduced,
Wang changed the model numbers of the 360K, 360KT and 360KR keyboard/display
units to 360/362K, 360/362KT, an 360/362KR. Another benefit was that Wang's
programmer units (the 370 and 380) were also compatible with the
362E (again, needing only paper keycap nomenclature changes for the
memory function keys), allowing the 362E electronics package to serve as
the core for a more-capable programmble calculating system.

The Wang 362E electronics package shares
a similar mechanical design to that of the Wang 360E. The electronics
package consists of briefcase-sized sheet-aluminum package with an attached
power cord, and a connector for plugging in the keyboard/display unit. A metal
carrying handle allows easier transport of the relatively heavy electronics
package, which weighs about 20 pounds.

The electronics package consists of
four main assemblies. The first is the chassis/cabinet, which is
made of heavy gauge stamped aluminum. The cabinet consists of three main
components, the chassis itself, serving as the foundation for the electronics,
and two covers, each of which are secured to either side of the chassis
by two screws each. The covers provide protection for the backplane and
the circuit boards.

The Power Supply Circuit Board

The next assembly is the power supply,
which consists of a fairly large transformer mounted separately, which
connects to a printed circuit board that contains the rest of
the power supply electronics. The power supply is a linear
design, using discrete power diodes for rectification of the
AC power coming from the transformer, large computer-grade electrolytic
capacitors as ripple filters, and simple resistive setpoints for the logic
supplies, which are +11 and -11 volts DC relative to ground. Another
section of the power supply generates approximately 250V to drive the
Nixie tube display in the keyboard/display unit.

The Backplane of the Wang 362E

The third major part
of the electronics package is the backplane. It seems that Wang Labs was
very comfortable with point-to-point wiring technology for many of the
300-series calculators. The backplane of the calculator consists of a
collection of 30-pin edge connectors, two for each circuit board (for
a total of up to 60 connections to each Logibloc) that have long
rectangular-shaped wire tails to which individual wires are connected
(via an interesting clip technology that both provides a mechanical connection
as well as a secure electrical connection) to provide the interconnections
between the various circuit boards that plug into the backplane.

Closer View of Backplane "Clip" Interconnect Technology

Some Wang
calculators, such as the 360E exhibited in the museum, used a printed
circuit board backplane, but the vast majority of Wang's machines seem
to use the tried-and-true point-to-point wired technology. It appears that
toward the very end of 300-series production, Wang switched over
to printed-circuit backplanes as another cost-cutting measure to keep
their aging machines as competitive as possible.

The Logiblocs that make up the Logic of the Wang 362E

Lastly, the electronics package contains
the "Logiblocs" (as Wang called their circuit boards) that contain the
circuitry of the calculator. There are 26 circuit boards, each of which
contains various sections of the calculator logic. Each fiberglass circuit
board measures approximately 6 1/4" by 3 3/4", and has printed circuit
wiring on both sides of the board. The front side of each board contains the
transistors (most of which are made by RCA), diodes, and various passive
components that implement the logic, as well as interconnecting traces.
The back side of the Logiblocs contains only
interconnection traces. Connections between the front and back sides of the
boards are made by traditional feed-through holes, which are plated through
the board to allow an electrical path through the hole. Each board has
two 30-pin groupings of edge-connector fingers to plug into the backplane.
The edge-connector fingers are tin-plated, which, while inexpensive, is not
nearly as reliable as gold-plated edge connector fingers. The tin fingers
tend to corrode, which causes excessive resistance in the connection between
the board edge finger and the connector the board plugs into. This corrosion
is the most common form of failure in the Wang 300-series calculators.
Simply cleaning the fingers with the appropriate contact cleaning solution
or, in lieu of that, a simple pencil eraser (gently used), can be the source
for fixes a great many of the problems that a malfunctioning machine may have.

The 362E benefits from design
reuse from earlier machines in the 300-series. In fact, of the 26
circuit boards in the 362E, 20 boards are identical to and interchangeable
with those used in the 360E. The core memory board in the 362E the same as used
in Wang's earlier 320SE electronics package, leaving only 3 boards that
are unique to the 362E. These three boards implement the unique memory
functions of the 362E. This efficient reuse of earlier designs allowed
a quick design time on the 362E, easier manufacturing, and little in the
way of additional training needed for service technicians, making the 362E
an economical "bridge" machine to keep Wang competitive in the marketplace
as the 300-series aged. However, while the 300-series architecture was
flexible enough to allow such hacks, the 362E represented the limits to
which the architecture could be stretched without major re-design.
The logic of the 300-series calculator is all hard-wired, meaning that
the sequential logic that carries out calculations is guided by various
logic devices wired specifically together to perform given functions.
The fact that the 300-series
calculators had hard-wired logic was another reason why Wang had to
scramble to come up with the 700-series to replace the 300-series.
Hewlett Packard used a microcoded architecture on their HP 9100 calculators.
A microcoded architecture uses a read-only memory (ROM) to store
micro-instructions that guide the calculator through the logical steps
of solving a problem. Microcoded logic architectures were originally
developed for large computers, to allow flexibility in the design of the
machines. The principle was applied to calculators, because by simply changing
the microprogram in ROM, the function and features of the calculator can
changed without having to re-wire the basic logic of the calculator.
Hewlett Packard leveraged a microcoded architecture in their amazing debut
electronic calculator, the HP 9100A. The introduction of this machine was the
trigger that sent Wang Laboratories into a panic to build a next-generation
replacement for the 300-series. Shortly after HP introduced the 9100A,
HP's engineers developed some minor microcode changes (along with a few minor
hardware changes), and introduced the 9100B, which
doubled the data and program memory capacity of the 9100A, and added
additional subroutine capabilities. The flexible microcoded architecture
used in the design of these machines allowed HP to make relatively
minor changes to the architecture of their calculator, and produce
a new model in a very short time that added significant functionality, without
having to change the fundamental architecture of the calculator.
The hard-wired logic of the 300-series calculators made feature changes
significantly more difficult. This, along with the other limitations
of the 300-seriers calculators, was a reason why the 362E
was the end of the line for the 300-series calculators -- the hard-wired
architecture had simply evolved to the point where any significant feature
changes beyond those made for the 362E would essentially require a whole
new design. This is why Wang chose a microcoded
architecture for the 700-series calculators, in hopes that such an architecture
would allow on-going updates to the features and capabilities of the
calculators as time went on. As it turned out, Wang's choice to go
with a microcoded architecture was the right one, as the 700-series
design evolved into follow-on machines including the
Wang 600-series and 500-series calculators which carried Wang's calculator
business well into the 1970's without significant architectural changes.

The "541" Core Memory Board Used in the 362E (Sense amplifiers on left, Inhibit Drivers on Right)

The logic of the 362E (like the
other members of the 300-series) centers around the core memory subsystem,
since all of the working registers of the calculator are stored there.
A series of binary counters with decoded outputs form sequencers that
direct the overall operation of the calculator. The logic is constantly
cycling through the core memory, sequentially reading the content of the
W (Working) register and displaying it on the Nixie tube display.
At the same time, the logic is looking for keypresses on the keyboard.
When a key is pressed, the logic of the machine 'shifts gears', continuing
the display process, but also performing other logical operations to carry
out the operation specified by the keypress. The core memory system
contains a total of sixteen 64-bit registers, four of which contain the
working registers of the calculator (W, L, Left Accumulator, Right Accumulator),
and the other twelve containing the memory storage registers. The core
array, which is arranged in four planes of 16 by 16 bits each, resides on
a single circuit board, along with four sense amplifiers and four inhibit
drivers. The row and column addressing circuitry for the core array
exists on four other circuit boards, with each board driving eight rows or
columns of the core array. Lastly, one more board contains (among other things)
the constant-current source that provides the current used by the row,
column, and inhibit drivers.

As with the other members of the 300-series,
the 362E allows a Wang CP-1 or
CP-2 Card Programmer to be connected in
series with the keyboard/display unit to provide simple programmability. Other
Wang 300 peripherals, including the IC-1
Item Counter, also will operate
with the 362E. The Wang 370 and 380 Programmer keyboard/display units
also operate with the 362E. These keyboard/display provide more complete
programming functions, including test and branch capabilities, and I/O
control. The programmers also provide interface to a wide range of
peripheral capability, including printers, additional external core
memory storage, Teletype interface, and much more.

The Wang 300-series was the true beginning
of Wang's early dominance of the high-end electronic calculator market.
Wang's first calculator, the LOCI, was a bit tedious to use, and while
it got Wang Labs into the calculator business, the refinements made to the
300-series calculators were the key that truly launched Wang into a lead
role in the market, generating countless millions worth of sales during their
lifetime, which spanned from 1965 through around 1973. While sales of
the 300-series machines continued into the mid-1970's, active development of
the line had ended by mid-1969. Back in those days, it wasn't
unusual for a manufacturer's calculator model to be replaced by a newer,
better machine in 12 to 18 months. The usable lifetime of the 300-series
calculators was truly amazing. The 362E may have been the last of it's
kind, but the longegity of it and the other members of the 300-series family
was a great testimony to the ingenuity of Wang Laboratories.

For more information on the operation
and history of Wang 300-series calculators, check out the Spec Sheet for the 362E, which has links other 300-series calculators
exhibited in the museum.